(No Model.) , M. BLAKEY. SEAMS OF PIPES, No. 433,591, Patented Aug. 5, 1890.

F. G.I. -

wiTNEsses: INVENToR, aw $ work % of 6.4. 2. Wei.

UNITED STATES PATENT OFFICE.

MILDRED BLAKEY, OF PITTSBURG, PENNSYLVANIA. WELDING SEAMS OF PIPES.

SPECIFICATION forming part of Letters Patent No. 433,591, dated August 5, 1890. Application filed May 1, 1890, Serial No. 350,147, (No model.) To all whom it may concern: grooves or passes suitably constructed accord Be it known that I, MILDRED BLAKEY, a ing to rules well known in the art, for the re citizen of the United States, residing at Pitts duction of the bar or billet to a strip star burg, in the county of Allegheny and State shaped in cross-section, as shown in Fig. 1. of Pennsylvania, have invented or discovered. The points or spurs can be closed or bent to 55 certain new and useful Improvements in ward each other in pairs bypassing the star Welding Pipes, of which improvements the shaped bars between suitable rolls, thereby following is a specification. forming grooves on opposite sides of the bar, The invention described herein relates to as shown in Figs. 2 and 3, for the reception O certain improvements in the manufacture of of the edges of the skelps. The strip or key Wrought or pipes or tubes, which, thus formed may be slid between the edges in accordance with the present practice, are of the skelp after it is bent into tubular form, formed by bending a strip of metal, or, as it or, and as I prefer, the strip is held in such is known, a “skelp, longitudinally into tu relation to the skelp-bending machine that bular form, and then welding the adjacent the edges of the skelp imay enter and slide longitudinal edges. These edges are joined along the grooves 2 of the strip or key as the either by a butt-weld or by a lap-weld. The skelp is drawn through the machine. After former is preferable when uniformity in the the skelp and key are adjusted together, as thickness of the walls of the pipe is desired, described, they are placed in a suitable fur but is objectionable on account of the diffi nace and heated to the proper temperature culty of making a good weld. The lap-weld and then welded together in the manner usual is preferable as insuring a good weld, but is in lap-Welding. objectionable for the reason that the edges Care should be taken in forming the skelps are liable to lap over too far, and hence the and the welding-key, as regards the width of 25 metal is stretched in forcing the ball through each, that the finished pipe shall be of the 75 during the welding process, and thereby re standard internal diameter, and that the ducing the walls in thickness. welding-key should be so proportioned as re The object of this invention is to combine gards its cross-sectional area that it can be the desirable features of both methods of reduced in the welding operation to the same forming pipes and avoid the objectionable thickness as the wall of the pipe. It is ob characteristics; and the invention consists in vious that the key I will effectually prevent uniting the edges of the skelp by a welding any change during the heating of the skelp key or strip, as will be hereinafter more fully as will render necessary any stretching of described and claimed. the metal during the Welding operation, and 35 In the accompanying drawings, forming a that therefore a uniformity of thickness of part of this specification, Figure 1 is a sec the pipe-walls incident to the ordinary butt tional elevation of my improved welding key weld can be attained in connection with the or strip as it comes from the rolls. Fig. 2 is superiority of weld inherent in the present a sectional view of a skelp having scarfed or lap-weld practice. The edges of the skelp beveled edges, showing the arrangement of may be scarfed, as shown in Fig. 2, or cut the welding-key between its edges; and Fig. square, as shown in Fig. 3. - / 3 is a similar view, the skelp having square I am aware that pipe have been formed by or unbeveled edges. bending the projecting arms of an H-section In the practice of my invention the strip strip of metal down behind flanges formed 45 or skelp is formed in the usual manner, ex along the edges of sheets or plates, as de 95 cept that it is made a little narrower to allow scribed in English Letters Patent No. 2,157 for the interposition of the welding key or of 1883. In this construction the locking strip 1, as will be hereinafter described. This strip engages ribs along the interior and ex welding key or strip is preferably formed by terior surface of the pipe, and cannot be re 5o a bar or billet between rolls having duced to a thickness uniform with that of the Ioc

2 433,591 metal sheet or plate, whereas in my construc sired uniform thickness, substantially as set tion the thickness of the pipe-wallis approxi forth. mately uniform throughout. 2. A welding key or strip having a groove In the practice of my invention the skelp along each edge for the reception of a prac 5 employed does not differ materially as regards tically plain-edged skelp, and approximating construction from the skelp as ordinarily in thickness the skelp to which it is to be ap made. plied with reference to its reduction in the I claim herein as my invention welding operation to the same thickness as 1. In the manufacture of wrought-iron pipes the skelp, substantially as set forth. 25 Io and tubes of substantially uniform thickness In testimony whereof I have hereunto set along the joints as elsewhere, a welding key my hand. or strip approximately of the thickness of the skelp to which it is to be applied and hav MILDRED BLAKEY. ing a groove in each edge thereof, in combi Witnesses: I5 nation with a practically plain-edged skelp, W. B. CORWIN, whereby a welding-pass will produce the de DARWIN S. WOLCOTT.